Carl gtjstaf patrik de layal



(No Model.)

0. G. P. DE LAVA]... WATER. TUBE BOILER.

No. 557,838. Patented Apr. 7, 1896.

v I 4W NITED STATES ATENT OFFICE;

CARL GUSTAF PATRIK DE LAVAL, OF STOCKHOLM, SW'EDEN.

WATER-TUBE BOILER.

SPECIFICATION forming part of Letters Patent NO. 557,838, dated April '7, 1896.

Application filed September 9, 1895. Serial No. 561,904 (No model.)

To all whom, it may concern.-

Be it known that I, CARL GUSTAF PATRIK DE LAVAL, a citizen of Sweden, residing at Stockholm, Sweden, have invented certain new and useful Improvements in IVater-Tube Boilers, of which the following is a specification.

The present invention refers to an improvement in water-tube boilers of that kind which consists of a single continuous tube in one end of which wateris pumped in, while steam issues from the other end, and which, moreover, is provided with magazine-firm g. In such boilers the magazine-tube must be surrounded by a part of the boiler water-tube in order to obtain that cooling of the magazinetube which is necessary to avoid its burning.

Xow the purpose of the invention is to admit of the raising and lowering of the magazinetube, and thus to control the thickness of the coal-layer upon the grate. To this end I provide a spirally or helically wound tube as the connection between the inner coils or section wound upon the magazine and the remaining part of the boiler water-tube, said spirally or helically wound tube having its few coils so separated by wide spaces and with so large a diameter in relation to the diameter of the watertube itself that it acts as a torsion-spring during the raising or lowering of the magazine-tube.

In the accompanying drawing a steamboiler with the improvement in question is shown in vertical section.

a is the continuous boiler water-tube, with the water-supply at b and the steam-outlet at c. In the example shown said boiler-tube consists of three cylindrical sections or spiralsnamely, one external spiral section a at the shell of the boiler, one internal spiral section a, surrounding the coal-magazine (Z for cooling it, and one spiral section a situated about in the middle between the two spiral sections a and In order to enable the varying of the thickness of the coal-layer upon the grate e, the coal-magazine d is movable in vertical direction up and down by means of any convenient arrangement. (Not necessary to be shown on the drawing.) The connection between the spiral section ta which is fixed on the magazine d so as to follow its movements, and the spiral section d (or a',) which is immovable, consists of a spirally or helically wound tube a having its few coils so separated by wide spaces or interstices and with so large diame ter in relation to the diameter of the tube itself that this tube acts as a torsion-spring when moving the magazine up and down. Thus a constant connection is provided between the several parts of the boiler watertube.

The blastair flows into the space beneath the grate through openin g f, and the products of combustion leave the boiler through opening g.

Having now particularly described my invention and in what manner the same is to be performed, what I claim is- 1. In water-tube boilers, the combination of a movable coal-magazine for controlling the height of the coal-layer on the grate, and a cooling spiral section fixed to and surrounding the magazine and forming a part of the water-tube of the boiler, substantially as set forth.

2. In water-tube boilers, the combination of a movable coal-magazine for controlling the height of the coal-layer on the grate, a cooling spiral section fixed to and surrounding the magazine and forminga part of the watertube of the boiler, and a spiral or screw-Wound water-tube composed of coils separated by spaces orinterstices and connected at one end with said cooling spiral section and at the other end with the fixed boiler water-tube, and adapted to act as a torsion-spring during the movements of the magazine,substantially as and for the purpose set forth.

3. In water-tube boilers, the combination of the fixed water-tube section a the movable water-tube section a surrounding the coal-magazine (Z for cooling it, and the spiral or screw-wound water-tube a composed of coils separated by spaces or interstices and connected at one end with said cooling Watertube a and at the other end with the fixed boiler water-tube section a and adapted to act as a torsion-spring during the movements of the magazine, substantially as and for the purpose set forth.

In testimony that I claim the foregoing as my invention I have signed my name in presence of two subscribing witnesses.

CARL GUSTAF PATRIK DE LAVAL. Witnesses:

TYRKO ROBSAHM, ALDEMAR BOMAN. 

